This application relates to a system for monitoring the operation of a ram air turbine.
A ram air turbine (“RAT”) is a component incorporated into an aircraft. The RAT is generally stowed within an aircraft body. A RAT includes a turbine which may be driven by airflow to rotate and cause rotation of an associated power generation rotor. In one application, the power generation rotor is an electric generator rotor adjacent a stator. In this way, electricity is generated. In another application, the power generation rotor is a hydraulic pump rotor.
The generated electricity may be utilized to provide electric power to critical components on an aircraft. In the hydraulic pump application, the hydraulic fluid powers critical components.
The RAT is typically moved from the stowed position to an extended position at which it extends outwardly of an aircraft body when an engine, or engines, associated with the aircraft fail. As can be appreciated, the great bulk of RATs are never utilized to perform this function as air travel is extremely safe.
However, when it is necessary for a RAT to operate, it is important that it be functional. As such, periodic testing of RATs is recommended.
To date, RAT manufacturers have set testing to be performed periodically. The period between tests is selected to be conservative and, thus perhaps more frequent than needed.
Typically, the test interval is between 12 and 24 months. The current test may be ground based with the turbine blades driven through some external motor. Alternatively, it is also known to test the RAT by deploying the system in flight.
The current tests thus present a cost and schedule burden to airlines.
Currently, a limited amount of data is collected during the test. As an example, typical collected data would be turbine speed, generator frequency, line contactor closure status, and the amount of power supplied from the generator.